Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infections in infants and small children. RSV infection is characterized by significant immunopathology which is mediated by CD8+ cytotoxic T lymphocytes (CTL). Past studies have suggested that CD8+ T cells with different functional properties and characteristics can be elicited following infection or immunization, and may have differential effects on viral clearance and RSV-associated illness. This study seeks to fully characterize CD8+ T responses to RSV, elucidate important factors that dictate the type of CD8+ T cell response that is generated, and understand how other cell types regulate the CD8+ T cell response to result in either a beneficial or a detrimental effect.